Abstract: Provided is a rotatable keypad assembly including a plurality of keybuttons used as a data input unit of a portable terminal. In the rotatable keypad assembly, a roller is rotatably installed at a predetermined position in the portable terminal and has a portion exposed outside the portable terminal. A keypad sheet is wound around the roller and has the keybuttons thereon. A knob is interlocked with one end of the roller and is rotated to expose the keybuttons corresponding to the exposed portion of the roller. Accordingly, it is possible to reduce the size, thickness and weight of the portable terminal without presenting any difficulty in using the portable terminal.